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排序方式: 共有336条查询结果,搜索用时 816 毫秒
31.
CM Heinicke M Goorsky S Moscov K Dudley J Gordon D Guthrie 《Canadian Metallurgical Quarterly》1998,68(4):534-541
Following up on previous work demonstrating that an intervention with at-risk mothers made a positive impact on the quality of mothers' partner support, responsiveness to the needs of the child, the child's expectation of being cared for, and child's response to a brief separation, the present paper examines whether quality of the mother's partner support mediated the impact of the intervention on these outcomes. 相似文献
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Acetone, propionitrile, pyrrole, and thiocyanate were selected as representative compounds of wastewater expected from pressurized, fluidized-bed hydroretorting (PFH) of Eastern oil shales. The PFH process has been the subject of investigation for the purpose of obtaining higher oil yields from Eastern shales than has been possible using conventional retorting methods. Preliminary batch experiments illustrated that acetone, propionitrile, pyrrole, and thiocyanate are aerobically biodegradable by heterogeneous microbiological cultures. The use of three continuous-flow activated sludge reactors to further evaluate the biological treatability of the synthetic waste revealed that the compounds could be removed at hydraulic residence times of as low as 1 day. Three 1 day experiments demonstrated the biological system's capability to accept organic shock loadings without a change in effluent quality. A no-recycle reactor illustrated that the flocculent microbiological population had a high resistance to solids washout. Because a supplementary nitrogen source was not included in synthetic waste treated by the no-recycle unit, it was shown that propionitrile, pyrrole, and/or thiocyanate supplied the nitrogen necessary for biological activity. 相似文献
34.
Weimin Si Michael Dudley Hua Shuang Kong Joe Sumakeris Calvin Carter 《Journal of Electronic Materials》1997,26(3):151-159
Synchrotron white beam x-ray topography (SWBXT) and Nomarski optical microscopy (NOM) have been used to characterize 4H-SiC
epilayers and to study the character of triangular inclusions therein. 4H-SiC substrates misoriented by a range of angles
from (0001), as well as (1 100) and (1120) oriented substrates were used. For epilayers grown on substrates misoriented by
3.5° from (0001) toward <1120>, the triangular inclusions were identified as consisting of two 3C-SiC structural configurations
which are related to each other by a 180° rotation about the [111] axis. The epitaxial relationships between the 3C inclusions
and the 4H-SiC epilayers (or substrates) were also determined. No evidence was found for the nucleation of 3C-SiC inclusions
at superscrew dislocations (along the [0001] axis) in the 4H-SiC substrates. Increasing the off-axis angle of the substrates
from 3.5 to 6.5° was found to greatly suppress the formation of the triangular inclusions. In the case of substrates misoriented
by 8.0° from (0001) toward <1120>, the triangular inclusions were virtually eliminated. The crystalline quality of 4H-SiC
epilayers grown on the substrates misoriented by 8.0° from (0001) was very good. For the (1100) and (1120) samples, there
is no indication of 3C-SiC inclusions in the epilayers. Possible formation mechanisms and the morphology of 3C-SiC inclusions
are discussed. 相似文献
35.
Selecting ratings for capacitors and reactors in applicationsinvolving multiple single-tuned filters
Bonner J.A. Hurst W.M. Rocamora R.G. Dudley R.F. Sharp M.R. Twiss J.A. 《Power Delivery, IEEE Transactions on》1995,10(1):547-555
This paper focuses on the selection of ratings for capacitors and air-core reactors used in multiple single-tuned harmonic filter configurations. Digital transient simulations of an example power system demonstrate the exceptionally high voltage and current stresses placed upon filter components in these configurations. Design guidelines for increasing the component ratings to account for the extra stresses are described. A comparison between traditional rating methods and the proposed methods are presented for the example system 相似文献
36.
NS Chang RJ French GM Lipkind HA Fozzard S Dudley 《Canadian Metallurgical Quarterly》1998,37(13):4407-4419
High-affinity mu-conotoxin block of skeletal muscle Na+ channels depends on an arginine at position 13 (Arg-13). To understand both the mechanism of toxin interaction and the general structure of its binding site in the channel mouth, we examined by thermodynamic mutant cycle analysis the interaction between the critical Arg-13 and amino acid residues known to be in the channel's outer vestibule. Arg-13 interacts specifically with domain II Glu-758 with energy of about -3.0 kcal/mol, including both electrostatic and nonelectrostatic components, and with Glu-403 with energy of about -2.0 kcal/mol. Interactions with the other charged residues in the outer vestibule were shown to be almost entirely electrostatic, because these interactions were maintained when Arg-13 was replaced by lysine. These results place the bound Arg-13 at the channel mouth adjacent to the P (pore) loops of domains I and II. Distance estimates based on interaction energies suggest that the charged vestibule residues are in relative positions similar to those of the Lipkind-Fozzard vestibule model [Lipkind, G. M., and Fozzard, H. A. (1994) Biophys. J. 66, 1-13]. Kinetic analysis suggests that Arg-13 interactions are partially formed in the ligand-channel transition state. 相似文献
37.
Park Denise C.; Royal Derek; Dudley William; Morrell Roger 《Canadian Metallurgical Quarterly》1988,3(1):94
Young and older adults were presented with pictures for study. Their recognition of the information was tested at five retention intervals: immediately, and 48 hr, 1 week, 2 weeks, and 4 weeks later. The main finding of interest was that picture recognition did not show an age-related decline until the 1-week retention interval. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
38.
Michael A. Perring Caroline H. Jackson 《Journal of the science of food and agriculture》1975,26(10):1493-1502
Data for bulked samples of ungraded Cox's Orange Pippin fruit obtained from many sources over a period of 18 years show that there is a general inverse relationship between mean mass per apple and mean calcium concentration. Part of the scatter around the regression curve was accounted for by differences between years but there were larger differences between samples of the same size picked from different orchards in the same year. Even with the most favourable conditions the observed samples with mean mass per apple greater than 150 g had less than 5 mg Ca/100 g when no calcium sprays were applied and in general most samples with mean masses per apple greater than 110g were likely to have concentrations of calcium below this and hence were liable to develop bitter pit. Fruit calcium level was a more important determinant of liability to bitter pit than was mean mass per apple. Although there was some evidence of the same relationship between calcium concentration and mass when apples from the same tree were analysed individually other factors often negated it. Two- to three-fold differences in calcium concentration were observed in individual apples from the same tree. 相似文献
39.
40.
PR Gibson JR Fraser JC Colman PA Jones G Jennings FJ Dudley 《Canadian Metallurgical Quarterly》1993,105(2):470-474
BACKGROUND: Hyaluronan is an endogenous polysaccharide whose clearance from the plasma is predominantly by liver sinusoidal cells and is sinusoidal flow dependent. This study was designed to determine if a change in serum hyaluronan might reliably reflect short-term drug-induced changes in sinusoidal perfusion. METHODS: Hemodynamic changes following an oral dose of ketanserin were compared with changes in serum hyaluronan levels in 12 patients with alcoholic liver disease and portal hypertension. Indices determined comprised heart rate, mean arterial pressure (MAP), cardiac output (CO), systemic vascular resistance, hepatic venous pressure gradient (HVPG), indocyanine green (ICG) clearance and extraction, and total hepatic blood flow. Measurements were made in a basal state 1 hour after ketanserin ingestion and expressed as a ratio of values post- to pre-ketanserin administration. RESULTS: Ketanserin had variable effects comprising both increases and decreases in all indices. On univariate and multivariate analysis, changes in serum hyaluronan concentration (1.05 +/- 0.13, mean +/- SD) significantly correlated with only one index: changes in ICG clearance (0.93 +/- 0.17, r = -0.65, P = 0.02). CONCLUSIONS: Changes in serum hyaluronan levels reflect short-term drug-induced changes in sinusoidal perfusion in patients with alcoholic liver disease and portal hypertension. Serial measurement of serum hyaluronan levels may offer a simple method of screening vasoactive drugs for their short-term effects on sinusoidal perfusion. 相似文献